CdSe/CdZnSe超晶格的激子光学性质的研究  

Exciton Optical Properties of CdSe/CdZnSe Superlattices

作　　者：张希清[1] 梅增霞[1] 段宁[1] 徐征[1] 王永生[1] 徐叙瑢[1] Tang Z K 

机构地区：[1]北方交通大学光电子技术研究所信息存储,显示与材料开放实验室,北京100044 [2]香港科学技术大学物理系,中国香港

出　　处：《光学学报》2002年第1期114-117,共4页Acta Optica Sinica

基　　金：国家自然科学基金;高等学校骨干教师资助计划基金资助课题

摘　　要：用分子束外延法在GaAs衬底上生长了CdSe Cd0 .65Zn0 .3 5Se超晶格结构。利用X射线衍射 (XRD)、77K下变密度激发的光致发光光谱和变温度光致发光光谱研究了CdSe CdZnSe超晶格结构和激光复合特性 ,在该材料中观测到激子激子散射发射峰 ,变密度激发光致发光光谱和变温度光致发光光谱证实了这一现象。激子发射峰的线宽随着温度的升高而展宽 ,低温时发光峰的宽度主要是由合金组分和阱垒起伏引起的 ,高温时激子线宽展宽是由于激子与纵光学声子和离化的施主杂质间的散射作用引起的 ,光致发光的强度随着温度的升高而降低 ,这主要是由激子的热离化造成的 ,也就是说 。CdSe/Cd 0.65Zn 0.35Se superlattices were grown by molecular beam epitaxy on substrate GaAs. The structure and exciton optical properties in high quality CdSe/CdZnSe superlattices are investigated by means of XRD spectra, photoluminescence spectra with different excitation power at 77 K and photoluminescence spectra with different temperature. The emission peak from exciton-exciton scattering is observed in CdSe/CdZnSe superlattices. It is validated by photoluminescence spectra with different excitation power and different temperature. The linewidth of the exciton emission becomes broader with increasing temperature. The linewidth at low temperature is due to the alloy composition and well thickness fluctuations, and the linewidth broadening at high temperature is contributed by the interactions among the exciton and LO phonons and ionized donor impurities. The photoluminescence intensities are reduced with increasing temperature, which is mainly due to the thermal dissociation of excitons, i. e., the electrons or holes jump from the wells into the barriers by thermal excitations.

关 键 词：光学性质 激子 超晶格 CdSe/CdZnSe 硒比镉 锌镉硒 半导体 

分 类 号：TN304.01[电子电信—物理电子学] O471.3[理学—半导体物理]